The present invention relates to an image input apparatus for picking up images of objects such as various kinds of documents, a person, and the like.
A conventional image input apparatus of this type will be explained below with reference to FIGS. 36 and 37. Referring to FIG. 36, reference numeral 301 denotes a lens; 302, a camera head which incorporates a CCD element and its circuit board (neither are shown); and 303, an arm which is constituted by a bellows- or spiral-shaped metal pipe. A signal cable is inserted through the arm 303, which can be bent to an arbitrary shape. Reference numeral 304 denotes a base which incorporates a main circuit board (to be described later) and is coupled to a chassis which also serves as a weight; 305, a monitor connected via a cable 306; 307, an original; 308, an operator or his or her position; and 309, an image of the operator as an object displayed on the monitor 305.
A portrait photographing operation as a typical use method of the conventional image input apparatus with the above-mentioned arrangement will be described below. First, the operator turns on a power switch (not shown) arranged on the base 304. Then, an image of the object (person) picked up by the camera head 302 is displayed on the monitor 305. In the case of FIG. 36, since the camera head 302 picks up an image of the photographer at the position 308, the monitor 305 displays the image 309 of the operator. At this time, a focusing ring provided to the lens 301 is turned to attain a focusing operation, as needed.
A document photographing operation for picking up an image of the original 307 placed on the desk will be described below. When the document photographing operation is performed, the operator holds the camera head 302 to move it to a position 302a indicated by a broken line in FIG. 36. Since the arm 303 is constituted by the bellows-shaped metal pipe that can be bent to an arbitrary shape, the operator can easily move the camera head 302.
The operator places the original 307 with respect to the camera head 302 moved to the position 302a, so that the lower side of the original is located on the base side (erected state when viewed from the base 304), as shown in FIG. 36. The original 307 must be placed in such direction since the CCD is attached to the camera head 302 to have a normal up-and-down direction in the portrait photographing operation. For this reason, in the document photographing operation, the up-and-down direction of the original 307 must be set in correspondence with the direction of the CCD, as shown in FIG. 36. With this adjustment, an image of the original 307 picked up by the camera head 302 at the position 302a can be displayed on the monitor 305 to have a normal direction, thus realizing a document photographing operation. At this time, the focusing ring provided to the lens 301 is turned to attain a focusing operation, as needed.
The internal arrangement of the base 304 will be described below with reference to FIG. 37. Referring to FIG. 37, the base 304 comprises a cylindrical portion 304a for holding the arm 303, and is fixed to a chassis 315 by screws (not shown). A main circuit board 316 is fixed to the chassis 315 by screws. Circuit boards 317, 318, and 319 are connected to the main circuit board 316 via connectors 320, 321, and 322, thus assuring a board area by effectively utilizing the internal space of the base 304.
The main circuit board 316 also has a connector 316a for receiving a cable (a flexible circuit board consisting of polyimide) for transferring signals from the camera head 302, and an image output terminal for receiving the cable 306 (FIG. 36). The chassis 315 comprises a substantially cubic block 315a consisting of a zinc-based material. The block 315a has not only a role of the bottom plate to which the main circuit board 316 and the base 304 are attached, but also a role of a weight that stably supports the entire apparatus.
However, the above-mentioned prior art suffers the following problems.
(1) The arm 303 has resiliency since it consists of a bellows-shaped metal member. For this reason, when the operator moves the camera head 302, the camera head 302 deviates slightly from the position intended by the operator due to the resiliency, i.e., so-called spring back. Therefore, the operator must repetitively adjust the position of the camera head 302, resulting in cumbersome operations. PA1 (2) In a normal document photographing operation, an A4-size (JIS) original is photographed to be fully displayed on the screen of the monitor 305. However, since the arm 303 is free to bend to an arbitrary shape, the operator has no reference for alignment, and a long time is also required for adjusting the position of the camera head 303 even in the normal document photographing operation. PA1 (3) Furthermore, in the document photographing operation, the lower portion of the original 307 must be set on the base 304 side, as described above. When the monitor 305 is present in the vicinity of the operator, the operator can give an explanation while observing the monitor 305. However, when the monitor 305 is located at a position separated away from the operator and the operator must give an explanation while reading the original 307, since the characters on the original 307 are in an upside-down state viewed from the operator, it is very difficult to read such document, thus disturbing a smooth explanation. PA1 (4) When the apparatus is carried while holding the base 304, the arm 303 rocks to the right and left due to the weight of the camera head 302. For this reason, it is not easy to carry the apparatus. In the worst case, the camera head 302 may be damaged upon colliding against the wall. PA1 (5) In particular, in the document photographing operation, the arm 303 to which the camera head 302 is fixed is constituted by a bellows-shaped metal pipe that is free to bend to an arbitrary shape, the camera head 302 moves freely and it is difficult to fix the camera head 302 at a given position. Furthermore, with this arrangement, the camera head 302 is easily influenced by an external vibration or the like. For this reason, the image displayed on the monitor 305 may vibrate, and becomes very difficult to observe. PA1 (6) When the operator wants to normally display an image of the original 307 on the screen of the monitor 305, he or she must change the position of the original 307 or must move the camera head 302 in a so-called trial-and-error manner while confirming the image of the original 307, resulting in tedious operations. In this manner, when the original 307 is placed, an alignment operation requires troublesome operations in association with the camera head 302, resulting in very poor operability. Also, in terms of assembling, since the cable or the like must be inserted through the bellows-shaped metal pipe that is free to bend to an arbitrary shape, the assembling efficiency is impaired, resulting in high cost. PA1 (7) Furthermore, in terms of reliability as well, since there is no means for regulating the rotation angle or the like of the bend portion, an excessive load is imposed on the cable, and the cable may be disconnected consequently.